I really would get rid of that late nap. And see if the daycare could start not letting her sleep for more than 2 hours if that doesn't fix it.
It seems like Lilah has needed 5 or 6 hours between sleep times for a while now... and that started somewhere around 14ish months. I know they're cranky when they lose a nap, but if I were you, I would rather put up with a cranky pants for a week or so than being up until midnight every night.
Do you think she's got some teeth coming in bothering her? Or about to have a verbal explosion or something? Lilah's sleep went to crap right around 15 months (or worse than it already was, anyway) and she started talking up a storm not much later. And then her sleep seemed to return to it's normal state.
Lilah 10/08 nursed 25 months
Beatrix 01/11 nursed 30 months